qemu-common.h: Remove include of cpu.h

The "qemu-common.h" included "cpu.h" when NEED_CPU_H was defined, which
introduced some nasty circular header dependency issues that affect later
patches in this series.

This patch removes the include, and fixes all other sources to include
"cpu.h" as needed instead.

+ Move loader declarations to "hw/loader.h"
+ Move some stuff from "qemu/timer.h" to "exec/cpu-all.h"

Change-Id: Ida1a4eccd889bae450b35ee32a931273ffe1f8d8
diff --git a/kvm-all.c b/kvm-all.c
index 428f25d..3ee3296 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -20,6 +20,7 @@
 
 #include <linux/kvm.h>
 
+#include "cpu.h"
 #include "qemu-common.h"
 #include "sysemu/sysemu.h"
 #include "hw/hw.h"